Moisture separator for air pressure lines



1958 Q G. ENGMAN 2,822,887

MOISTURE SEPARATOR FOR AIR PRESSURE LINES Filed Dec. 1, 1955 2Sheets-Sheet 1 J /6 52 h /7 49 e. 2m 2 Z i *5; 39 4/ 1 as 1/3/ 32 37 458'29 26 ,0 24 27 I0 Anvenlor Gerald Eggman ib .7-v

Feb. 11, 1958 v G. ENGMAN 2,822,887

MOISTURE SEPARATOR FOR AIR PRESSURE LINES Filed Dec. 1, 1955 2Sheets-Sheet 2 Anveazim Gerald 15:1 man Wilma! b 7 J 97 dil'l'orn UnitedStates Patent MDISTURE SEPARATOR FOR AIR PRESSURE LINES Gerald Engman,Des Moines, Iowa Appiication December 1, 1955, Serial No. 550,393 9Claims. (Cl. 183-41) This invention relates to a device for separatingwater from air pressure lines and more particularly to a separator thatwill automatically compensate for variations in pressure lines and/orthe sizes of exit orifices at point of use.

Compressed air as a source of power has many uses today such asoperating spark plug cleaners, paint spray guns, powered hand tools,grease guns and the like and in these uses it is highly essential thatthe air at the point of use be free of moisture, grit, sludge, rust orthe like. It is well known that moisture will condense out of compressedair and the amount of condensation will 'vary in proportion to thedistance the air must travel to the point of use, changes of temperaturealong the air line and other causes. Consequently, if moisture ispermitted to be discharged with the air at the point of use, seriousdamage and inefficient results can and will frequently occur.

The use of water removal means in air pressure conduits is not new. Anexample of such means is found in Churchman Patent No. 2,636,571, issuedApril 28, 1953, on a combination filter and trap. While the Churchmandevice worked quite successfully with a given air pressure, a given linecapacity, and a given orifice size, it was not successful when suchfactors varied. The Shaw Patent Number 2,669,320, issued February 16,1954, on a water separator and filter for air pressure lines, attemptedto cure this objection found in the Churchman structure. The Shawcompensating means utilized an adjustable valve manually operatedoutside the separator housing. To obtain the desired results, however,was by the trial and error method. Also the average workman had no ideawhat he was doing when he rotated the valve stem. In fact it usuallyrequired the services of an expert to properly adjust the device andeven when properly adjusted, users were constantly getting the mechanismout of proper adjustment.

Therefore, one of the principal objects of my invention is to provide amoisture separator for air pressure conduits that will automaticallycompensate and adjust for varying conditions of the line, the pressureand the size of the orifice at point of use.

A further object of this invention is to provide a combination waterseparator and filter through which air under pressure flows from asource of supply to a point of use and wherein any moisture, sludge,grid, rust or the like is filtered from the compressed air andautomatically discharged from the airflow line at times.

it is still another object of the invention to provide a combinationfilter and trap through which air under pressure flows in passing to apoint of use wherein any moisture in the compressed air is filtered fromthe compressed air and collected in a trap with said trap openedautomatically by the differential of pressure existing between .theinlet and outlet of the combination filter and trap when compressed airis withdrawn from the pipe line at the point of use.

A still further object of this invention is to provide a combinationwater separator and filter through which air under pressure flows from asource of supply to a point of use and wherein any moisture, sludge orthe like is filtered from the compressed air and collected in a-trapfrom which point it is automatically discharged andwhich separator andfilter is designed to permit a bleeding 'or slight leakage of themoisture from the tray 'to a collecting chamber during any prolongedoperation of the device at the point of use and from which-chamber itwill not only drain by gravity during such prolonged operation but willbe discharged 'by air pressure when the device at the pointof use isstarted or stopped.

Still further objects of this invention are to provide -a combinationwater separator and filter for drying and filtering compressed air in anair pressure line and automatically discharging the moisture therefromwhich is economical in manufacture, simple in construction, easily andquickly installed, efficient in operation, easy and economical torepair, and design for long usage.

These and other objects will be apparent to those skilled in the art.

My invention consists in the construction, arrangement, and combinationof the various parts of the 'device, whereby the objects contemplatedare attained as hereinafter more fully set forth, pointed out in myclaims, and illustrated in the accompanying drawings, in which:

Fig. 1 is a perspective view of my device installed in an air pressureline.

Fig. 2 is a vertical sectional view of my moisture separator and morefully illustrates its construction,

Fig. 3 is an enlarged perspective view of the flutter valve head means,

Fig. 4 is a side sectional view of the flutter 'valve means in a raisedposition,

Fig. 5 is a side view of the device with its housing broken away toexpose certain interior-parts,

Fig. 6 is a cross sectional view of the device taken on line 66 of Fig.2, and

Fig.7 is an enlargedcross sectional view taken on line 7-7 of Fig. 2. 7

Referring to the drawings, I have used the numeral 10 to designate ahousing provided with the chamber 11 and a reduced chamber portion 12below chamber 11 which results from the circumscribing ledge 13 that ismachined in the lower inner portion of the housing 10, as shown in Fig.2. The numeral 14 designates a centrally located opening provided in thebottom of the housing 10.

One side of the upper portion of the housing 10 is provided with theinlet 15 that is designed to communicate with a hose or pipe 16conducting air under pressure from a source of supply. The other side ofthe housing 10, at a point substantially diametrically opposite to theinlet 15, is provided with the outlet 17 that is designed to communicateat one end with a hose or pipe or the like 18 conducting compressed airto a point of use and extends at its other end upwardly through the topof the housing 10 at the point 19 as shown in Fig. 2.

The numeral 20 designates a housing provided with the chamber 21 and theoutlet 22. The housing 20 is designed to be detachably secured to thetop of the housing '10 by any suitable means such as the stud screws 23.When the housing 20 is so arranged the outlet 22 in the housing 20 willbe in line and communicate with the outlet 17 at the point 19, as shownin Fig. 2.

The numeral 24 designates a rubber washer resting on the ledge 13 andthe numeral 25 designates a circular metal plate member provided with aninverted lip portion 26 about the underside of the periphery thereof anddesigned to snugly fit within the housing 10 with the lip ledge 26resting on the rubber washer 24, as shown in Fig. 2. The plate 25 isprovided with the centrally located opening 27.

A cylindrical filter housing 28 providedwith a detachable bottom member29 and cover member 30 is positioned within the chamber 11 and rests onthe plate 25. The filter housing 28 is further provided with a pluralityof spaced apart holes 31 in its side wall.

Peripheral flanges 32 and 33 are formed on the bottom 29 and cover 30respectively, to frictionally engage the top and bottom rim portion ofthe filter housing 28. This filter housing 28 is formed from a wideresilient metal band that has its free ends in spaced relation. When thebase 29 and cover 30 are placed in their respective posi tions'on thefilter housing 28 the free ends of the housing are pushed together andthe tendency of the band to expand thereby increases the frictionalrelation between the housing and the base and cover respectively.

The bottom 29 extends radially inwardly and upwardly to a center openingcircumscribed by the upwardly extending circular collar flange 34. Thecover 30 extends radially inwardly and downwardly to a centrally locatedopening circumscribed by the downwardly extending circular collar flange35.

The numeral 36 designates a plurality of holes arranged near theperiphery of the bottom 29 and inside and closely adjacent the flange32. The numeral 37 designates a cylindrical shaped baflle member securedat one end to the inside of the cover 30 between and spaced apart fromthe flange 33 and flange 35 and extending vertically downwardly towardsbut short of the bottom member 29, as shown in Fig. 2.

The numeral 38 designates a cylindrical shaped mesh screen filter memberthat is vertically positioned within the filter housing 28 so that oneend embraces the flange 34 on the bottom 29 and the other end embracesthe flange 35 on the cover 30. A portion of the screen filter 38 is thusinside the baflle 37.

A second cylindrical shaped mesh screen filter member 39, larger indiameter than filter 38 is also vertically positioned within the filterhousing 28 so that one end rests on the inside of the bottom 29 and theother end engages the inside of the cover 30. In this position thebaffle 37 will be spaced apart and inside of the filter 39.

When the filter element is arranged and positioned as herein describedthere will be a space 40 in the chamber 11, between the inside of thehousing and the outside of the filter housing 28, as shown in Fig. 2 andFig. 4.

The numeral 41 designates a valve stem having a reduced lower sternportion 43. A valve head 44 on the bottom of the valve stem 41 isprovided with a conical shaped valve top portion 45 and a resilientvalve seat portion 46 on the bottom thereof. The numeral 42 designates awell in the top of the valve stem 41. Threaded into this well is thehollow nut member 49. The numeral 51 designates a flexible resilientdiaphragm between the cap 20 and housing 10 to divide the same into anupper chamber 21 and the intermediate chamber 40. The numeral 12designates the lower chamber. The hollow nut 49 extends through thecentral area of the resilient gasket diaphragm or flexible wall 51 andis connected thereto as shown in Fig. 2, by the diaphragm being clampedbetween the valve stem unit and nut 49. Slidably mounted in the well 42and the nut 49 is the flutter valve unit or piston 55 having an enlargedrectangular head 56 inside the well and an enlarged irregular head 57inside the hollow nut 49. The numeral 58 designates air passageways inthe valve stem communicating with the inside bottom of the well 42 andthe inside of the chamber 40. In the upper portion of the nut 49 arelateral air passageways 59 communicating with its inside and the chamber21. When the head 57 is in lowered position, the passageways 59 areclosed and when in a raised position the passageways are open as shownin Fig. 4. The numeral 60 designates a coil spring having one endbearing on the inside bottom of the nut 49 and its other end bearing ontop of the head 57, for yieldingly holding the flutter valve downwardlyin its vertical sliding movement. The numeral 61 designates an airpassageway extending vertically through the head portion 56. This hole61 connects with an air passageway 62 laterally extending through theside of the flutter valve stem above the head 56. This hole 62 is smallin diameter relative to the air passageways 58.

The practical operation of the device is as follows: It is firstarranged in an air pressure line so that the inlet is incommunication'with a source of air under pressure that is conductedthrough the hose or pipe or the like 16 and the outlet 17 is incommunication with a hose, pipe or the like 18 that conducts thecompressed air to a point of use, such as a paint spray gun, poweredhand tools or the like. Thus, the compressed air will pass through myseparator and filter before it reaches the point of use. Preferably,this device should be placed in the air line as close as possible to thepoint of use so that the air after leaving the separator will have nogreat distance to flow before being used and thereby reducing thepossibility of additional moisture forming in the air line between theseparator and point of use.

The position of the valve seat 46 in the chamber 12 when no air isflowing is illustrated in Fig. 2. The reason for this is that the airpressure Within the chambers 11, 12 and 21 respectively is equal, andconsequently the pressure on both sides of the diaphragm 51 is the same.

Air will enter through inlet 15 into the space 40. From the space 40 itwill pass through the holes 31 in the filter housing 21, and thencethrough the larger mesh screen filter 39. After passing through thefilter 39, the air will be directed downwardly by the baflde plate 37and under this baffle to pass through the smaller mesh screen filter 38.As the air passes through the filter 38 it will be in position to bereleased through the passageways 58, as will later be described indetail.

The path of the air flow through the filter element just described willcause the moisture, sludge, grit, rust or the like to be separated andfiltered therefrom and to collect on the inside of the bottom 29 of thefilter housing 28. The bottom 29 slopes from the center openig thereindownwardly to the periphery thereof where the holes 36 are located.These holes 36 provide an outlet path for the moisture from the bottom29 in addition to the central opening in the bottom 29.

When air is released at the point of use the position of the valve seat46 is illustrated in Fig. 5. As this air is released through the outlet17, the pressure above the diaphragm 51 in the chamber 21 becomes lessthan the pressure below the diaphragm, thereby causing the valveassembly to travel to its upwardly position. As this occurs, the conicalportion 45 on the valve head 44 will seat in the underside of theopening 27 in the metal plate 25. This will move the valve seat 46 offof the opening 14 in the housing 10 and will expose the chamber 12 tothe atmosphere. When this occurs there will be a distinct snap or sharpreport due to a momentary rush of air from the chamber 12 to the outsideatmosphere because while the valve assembly is in its upwardly positionthe chamber 11 will be substantially sealed off from the chamber 12 bythe seating of the conical portion 45 in the opening 27 so that thepressure in the chamber 12 will be reduced to substantially that of theatmosphere. In this initial rush of air from the chamber 12, moisturethat has collected therein will be blown out through the opening 14.

The valve assembly will remain in its upwardly position as long as airis released at the point of use. The reason for this is that the air iscontinually entering the filter as described and passing out through thepassageways 58 and 59 into the chamber 21 and thence through the outlet22 into the outlet 17, and during this time the pressure above thediaphragm 51 will be sufiiciently less than that below it to hold thevalve assembly up.

7 below, it will blast the valve assembly downwardly to its lowerposition. As this occurs and during the time interval that it takes thevalve seat 46 to be seated in the opening 14 the moisture or the likecollected on the bottom 29 will 'be blown through the holes 36, thecenter opening of the bottom 29, thence through the opening 27 in thewasher 25 and discharged through the opening 14. The distance of travelof the valve seat 46 is short but the concentrated pressure built upwhen the air flow is stopped is suflicient to produce the discharge justdescribed.

In order to obtain a satisfactory discharge of moisture or the like whenthe air flow is stopped, as just described, it is essential that thisdevice be positioned within a very few feet from the point of use. Thereason for this is to insure the proper pressure in chamber 21 due toinertia when the flow of air at the point of use is stopped. If thepoint of use is too far from this device, pressure in the flow line willbuild up slowly when the air flow is stopped, and instead of the valveseat 46 being blown downwardly it will merely slowly flutter to itsclosed position. However, this will not impair the operation of myinvention because when the air flow is again started, any moisturecollected in this device will be blown out as previously described. Butsince this device is capable of discharging moisture both at thestopping and starting of the flow air, it is preferably located near thepoint of use to obtain the full advantages of which it is capable.Likewise, the location of this separator and filter close to the pointof use serves the additional useful purpose, previously described, ofreducing the possibility of moisture condensing in the air line betweenthis device and the point of use.

After the valve seat 46 is seated the pressure within the separator willequalize and when air is again released at the point of use, theoperation just described is repeated. After a prolonged operation, orfor any other reason, if it is believed that all of the moisture has notbeen discharged, it is merely necessary to start and stop the flow ofair one or more times and this will discharge any moisture or the likethat might still be inside the device.

The fact that the distance of the device from point of use affects itsoperation is indicative that there are also other factors that must beconsidered. They may well be the size of the air conduit, the normalmaintained pressure at source, and certainly the size of the exitorifice. Obviously, the major portion of the air flow will always beable to pass through the air passageways 58, thence into the valve stemwell 42, thence up along the side of the flutter valve stem 55, andthence through the passageways 59 into the chamber 21. However, theflutter valve has a great equalizing or stabilizing function toautomatically take care of such above variations and thus eliminatemanual adjustments. The spring bearing downwardly on the flutter valvehead member 57 will tend to yieldingly close the passageways 59. Alsothis yielding action will tend to hold the head portion 56 of theflutter valve in closed position over the outlet of the merging airpassageways 58. However, even with the flutter valve in such loweredposition a small amount of air can pass from the passageways 58, throughthe air passageways in the flutter valve and into the well 42 and nut 49and around the central area of the flutter valve. This air underpressure will lift the flutter valve accordingly, elevating the head 57to expose the air passageway 59. By the head 56 being rectangular themajor portion of the air will pass around it when it is raised from itsvalve seat as shown in Fig. 4. Thus the flutter valve unit willreciprocate to iron out the extreme variations encountered. The resultis a valve mounted within a valve and. when the main valvegi. e};

the member 41, reciprocates, it will accordingly carry the valve 55.

If it is desired to convey the water to a dlstance away from the devicea conduit 65 may be secured over the opening 14. To facilitate theentrance of air in volume into the chamber space 40 the member 28 may bem dented adjacent the opening 15.

Some changes may be made in the construction and arrangement of mymoisture separator for air pressure lines without departing from therear spirit and purpose of my invention, and it is my intention to coverby my claims, any modified forms of structure or use of mechanicalequivalents which may be reasonably included within their scope.

I claim:

1. In a device of the class described, a an air inlet opening, outletopening,

housing having,

municates with said air inlet opening and the other with said air outletopening, a pressure difierential operated valve for controlling flowing, means for connecting said valve to said flexible wall for movementtherewith, said means having a passageway therein providingcommunication between said first and second compartments, a pressureresponsive recipro cating valve in said passageway for opening saidpassage in response to pressure in said first compartment, and a springmeans for yieldingly holding said reciprocating valve in a closedposition.

2. In a device of the class described, a housing a detachable lid cover,an inlet opening, an air outlet opening and a water outlet openingprovided in said housing, a flexible wall inside said housingintermediate said cover and said housing to form an upper and lowercompartment therein; said lower compartment in communication with saidair inlet opening and said upper compartment in communication with saidair outlet opening, a filter means arranged within said lowercompartment intermediate said air inlet opening and said air outletopening, a plate member arranged in said lower compartment to form anupper and lower chamber therein; said plate member provided with anopening to permit communication between said chambers, a pressuredifierential operated valve assembly in said housing, said assemblyincluding a first valve in said lower chamber for controlling flowthrough said water outlet and between said upper and lower chambers, astem extending through said plate and said filter means connecting saidvalve to said flexible wall for movement therewith, said stern having apassageway therein providing communication between said upper and lowercompartments, a pressure responsive reciprocating valve in saidpassageway for opening said passage in response to pressure in saidlower compartment, and a spring means for yieldably holding saidreciprocating valve in a closed position.

3. In a device of the class described, a housing having an air inletopening, an air outlet opening and a water outlet opening, a flexiblewall inside said housing dividing said housing into two compartments oneof which communicates with said air inlet opening and the other withsaid air outlet opening, a pressure differential operated valveassembly, said assembly including a valve for controlling flow throughsaid water outlet opening, a bore connecting said valve to said flexiblewall for movement therewith, an air passageway connecting its bore withthe compartment that communicates with said air outlet, an airpassageway connecting its bore with the compartment that communicateswith said air inlet, a pressure responsive reciprocating piston valve insaid bore for opening said passage in response to pressure in said firstcompartment, and a spring means for yieldingly holding saidreciprocating valve in a closed position.

4. The structure of claim 3, wherein said second menhaving an air outletopening and a water a flexible wall inside said housing dividingf saidhousing into two compartments one of which comthrough said water outletopentioned airpassageway connects the bottom of its bore with thecompartment that communicates with said air inlet.

5. In a device of the class described, a housing having an air inletopening, an air outlet opening and a Water outlet opening, a flexiblewall inside said housing dividing said housing into two compartments oneof which communicates with saidair inlet opening and the other with saidair outlet opening, a pressure difierential operated valve assembly,said assembly including a valve for controlling flow through said wateroutlet opening, a bore connecting said valve to said flexible wall formovement therewith, an air passageway connecting its bore with thecompartment that communicates with said air outlet, an air passagewayconnecting the bottom of its bore with the compartment that communicateswith said air inlet, a pressure responsive reciprocating doubleheadedpiston valve slidably mounted in said bore having one head adapted toclose said-first air passageway and its other head adapted to close saidsecond air passageway in response to pressure in said first compartment,and a spring means for yieldingly holding said piston valve in onedirection of its sliding movement.

6. The structure of claim 5, wherein said piston valve has an airpassageway extending through one of its heads.

heads and said passageway communicates with said sec- 0nd mentioned airpassageway.

8. The structure of claim 5, wherein said piston valve has an airpassageway extending through one of its heads and communicates with saidsecond mentioned air passageway, said air passageway in said pistonvalve having a capacity substantially less than the capacity of saidsecond air passageway.

9. The structure of claim 5, and perforated filtering members embracedin said first mentioned compartment.

References Cited in the file of this patent UNITED STATES PATENTS2,629,453 Allen et al. Feb. 24, 1953 2,636,571 Churchman Apr. 28, 19532,669,320 Shaw Feb. 16, 1954 2,700,987 Whalen Feb. 1, 1955

